<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>太极</title>
    <style>
        body {
            background: skyblue;
        }

        .con {
            width: 400px;
            height: 400px;
            border-radius: 50%;
            /* background: linear-gradient(white 50%, black 50%); */
            /* 线性渐变 */
            background-image: linear-gradient(to right, white 50%, black 50%);
            margin: 50px auto;
            position: relative;
        }

        .left {
            width: 200px;
            height: 200px;
            /* 径向渐变 */
            background-image: radial-gradient(circle, white 25%, black 30%);
            border-radius: 50%;
            position: absolute;
            /* top: 100px;
            left: 0; */
            top: 0px;
            left: 100px;
        }

        .right {
            width: 200px;
            height: 200px;
            background-image: radial-gradient(circle, black 25%, white 30%);
            border-radius: 50%;
            position: absolute;
            /* top: 100px;
            right: 0; */
            bottom: 0;
            left: 100px;
        }
    </style>
</head>

<body>
    <div class="con">
        <div class="left"></div>
        <div class="right"></div>
    </div>
</body>

</html>